Tuesday, September 21, 2010

The Mighty Skywarrior

The Whale was the result of a U.S. Navy program to develop a carrier-based, long-range, nuclear bomber. It had a very long career. Originally intended to operate from a super carrier, United States, it was downsized to be compatible with Midway-class carriers and with the advent of steam catapults and angled decks, based on the carriers as small as the Essex-class 27 Charlies.

Production ended in 1960. There were two basic airframes, the Bombers and the so-called Versions. The Versions were special mission aircraft, with the Bombers also being relegated to a support mission role very early in the Vietnam War.

A Version was clearly distinguishable from a Bomber because the former was designed for a higher level of pressurization, externally most evident by the canopy framing. The canopy of the Bombers had skinny frames and a large rectangular sliding hatch; the Versions' canopy had heavier frames and the hatch was small, square, and inward opening. The higher level of pressurization was also evident in the structure of the boarding ladder/escape slide.

The canopy structure of both the Bombers and the Versions changed over time due to the relocation of the sextant port for celestial navigation. The last 21 Bombers were built with a sextant bubble in the left rear position and many were retrofitted with it while retaining the original sextant port; none of the Versions were originally produced with this feature but many were retrofitted.

The Versions Retrofit canopy shown above needs to be revised. It is correct for the A3D-2P/

RA-3B. Some A3D-2Q/EA-3Bs were retrofitted with the additional framing over the third crewman but there was no sextant port at that position. The sextant port was retained at the assistant pilot position instead.

The Bomber configuration varied considerably over time. There wasn't any external difference between the A3D-1 and the -2 initially. The designation change was primarily due to installation of an uprated J57 engine. (For background on the -1, see http://tailspintopics.blogspot.com/2013/06/blue-whales.html) The first notable external difference was the addition of the capability to be refueled in flight since this applied to the A3D-2 only with the exception of at least one A3D-1 (BuNo 130353 was equipped with a probe for flight test evaluation). However, provisions for the refueling probe were not originally installed on early A3D-2s and deployed Skywarriors were not fitted with them initially. Likewise, the DECM or "Dove Tail" was incorporated in late production A3D-2s and retrofitted to earlier ones along with the subsequent DECM nose. The addition of the DECM tail was not accompanied by a small rearward facing antenna on the vertical fin tip as I had previously thought (it was incorporated along with the "L"-shaped antenna on the later nose) but the small inlet on the dorsal fin may have been added at that time.

From BuNo 142650 and subsequent for both Bombers and Versions, the fuel vent, which had been a small vertical mast on the lower surface of the left horizontal stabilizer, was changed to a large horizontal mast on the left rear fuselage. It doesn't appear to have been retrofitted. For some pictures and discussion on this, see http://tailspintopics.blogspot.com/2013/05/a3d-fuel-vent.html

Provisions for the tanker package on the Bombers were also incorporated at BuNo 142650 with no designation change. When the tanker package was retrofitted on earlier Bombers as a permanent installation, the modified aircraft were designated KA-3B.

Other antennas came and went. As a result, a given Bomber may vary in detail from the following...

Rick Morgan notes that "many EKA-3Bs lost their distinctive ALQ-92 side blisters after 1972 but kept the belly canoe and its systems, remaining EKA-3Bs. You tend to see a lot of captions that mistake late EKAs for KAs. Many of the EKAs eventually lost all of their jamming systems and reverted to true KA status from about 1974; many of these airframes went to the two Reserve units which, despite their original VAQ titles, never had EKAs. If you look closely at later VAK-208/308 birds, many showed scars from where the ALQ-92 blisters had been."

The Versions' fuselage was very different internally, with the forward fuel cell moved aft to create a large pressurized compartment immediately behind the cockpit. The entrance door was relocated forward about 20 inches. On the A3D-2T and the A3D-2Q, an escape hatch was added to the top of the fuselage and a bailout door was incorporated on the right side of the fuselage for the cabin occupants. On the A3D-2P, the forward part of the cabin area was filled with cameras. The aft part was used for small side-by-side bomb bays containing flash cartridges for night photography.

The redesign was accompanied by other detail changes. All A3Ds used bleed air to turn two air turbine motors (ATMs) to generate the required electrical and hydraulic power. On the Bombers, the two ATMs were located side-by-side facing outboard on the left side of the fuselage. The exhaust ports were small round holes below and behind the cockpit. On the Versions, the ATMs were located below the cockpit, with one rectangular vent on each side of the forward fuselage. The Versions were also equipped with a deployable Ram Air Turbine for emergency power. It was located on a small door below the right ATM exhaust port. (The Bomber relied on battery power if both ATMs failed.) The Versions also had much larger brakes that extended a few inches out past the wheel hub. See http://tailspintopics.blogspot.com/2013/05/douglas-a3d-skywarrior-main-landing.html. The aft end of the refueling probe fairing extended farther aft than on the Bombers because of the relocation of the forward fuel tank

The Versions also had a small inlet on the bottom of the aft end of the radome that was not present on the Bombers (this is a picture of an RA-3B (A3D-2P) so it also has the view ports for the camera aiming periscopes).

The A3D-2T did not have dual controls. It was a trainer for bombardier and navigators. It did have a unique flight deck arrangement, with the third crewman position behind the pilot facing forward instead of aft. The ASB-1 bombing system position was relocated to the cabin, which also accommodated stations for three other students and an instructor. Wing pylons were provided to carry practice bomb containers. (For more, see http://tailspintopics.blogspot.com/2013/09/ta-3b-skywarrior.html)

A slightly different wing was introduced during the production of the A3Ds, both Bombers and Versions. It had a cambered leading edge (CLE) airfoil, with the wing chord increased by a few inches perpendicular to the wing, more at the root than the tip. See the table above for the effectivity. Also see http://tailspintopics.blogspot.com/2013/06/a3d-3-skywarrior-wings.html

A slat was added between the fuselage and the engine pylon and the configuration of the outboard slats changed as well.

(Note: Douglas factory drawings were not perfectly consistent, so there may be small errors in the above; any minor deviation from the Trumpeter or Hasegawa kit features should not necessarily be considered correct)

The benefits were a slightly lower stall speed and wind-over-deck requirement for takeoff and landing. Combat ceiling was also improved by about 1,000 feet. Maximum speed was a few knots slower. See BuNo chart above for aircraft that were built with the CLE wing. The CLE wing was not retrofitted (except for Douglas flight test evaluation on BuNos 138918 and 138938) but I wouldn't rule out the replacement of a wing on a non-CLE A-3 with one from a CLE A-3 at some point in a long service life.

As shown in the opening picture above, the A3D sometimes sported old-fashioned wire antennas. These high frequency radio antennas don’t appear on early bombers because the HF antenna was originally enclosed in the leading edge of the vertical fin. They are present on some KA-3s and EKA-3s and also some of the Versions (one appears to have been part of the mission equipment suite of the A3D-2Q.). It was either a late production introduction (the last 20 non-CLE wing and all CLE-wing bombers?) and/or a retrofit. The forward connection of the upper antenna was on the rear edge of the left side of the canopy fairing, so it was just to the left of the bomber’s sliding hatch when it was open; if there were two antennas, the other terminated on the right side of the canopy fairing (there appear to be exceptions.) The upper antenna terminated on a post on the left side of the vertical fin just behind the leading edge antenna cover and below its top. The lower antenna usually terminated on the left side of the fin just behind leading edge antenna cover and just above the fin-fold joint but sometimes it terminated on the right side. The lower antenna was not always present when the upper antenna was and vice versa, although if there was only one antenna, it was usually the upper one. For more on antennas, including illustrations, see http://tailspintopics.blogspot.com/2015/06/a3d-3-wire-antenna-configurationa.html

The introduction of the RA-5C resulted in surplus RA-3Bs. The ERA-3B, not to be confused with the EKA-3B, was a highly modified Skywarrior used to provide simulation of enemy electronic warfare during fleet training exercises. All the reconnaissance hardware was removed from the camera compartment and an ECM operator station was added there along with a jump seat; a subsequent modification reportedly replaced the jump seat with a standard one.* Since this compartment was now occupied (although there had reportedly been a jump seat there when it was an RA-3B), the overhead emergency-egress hatch provided on the EA/TA was incorporated.The TA wing pylons were added to carry jamming pods. Due to the addition of all the avionics and externally mounted antennas and ram air turbines, the ERA-3B was deemed too heavy to land on aircraft carriers so it was shore-based.

* Revised in accordance with comments by MadDogVAQ33 and Anonymous provided below.

(Photo by Phil Friddell)

Both the 1/72 Rareplanes vacuform and the Hasegawa injection-molded A3D kits were produced using excellent factory drawings that I provided. The Rareplanes kit was one of Gordon's first with decals (a few unique black markings only for a VAH-4 KA-3B deployed on Kitty Hawk) and low-pressure molded landing gear struts. The overall shape is very good. The wing slats were the early configuration but defined by raised lines so a CLE wing would be just as easy to create. The canopy was for the later bomber configuration but unfortunately it was formed from a clear plastic that has yellowed over time so it would have to be replaced in any event. The kit included parts for the A3D-2P (RA-3B) camera ports and the EA-3B large "canoe".

The Hasegawa kit was issued in at least four different configurations but all were Bombers or modifications of Bombers such as the KA-3B and EKA-3B via extra parts. The canopy is the later Bomber canopy. The wheel brakes are the ones originally used on the Versions, but it may be that the later Bombers were fitted with them as well. The slats are depicted by fine engraved lines, rather than being extendable**, with a CLE wing slat represented inboard of the engine nacelle and non-CLE slats outboard. Not withstanding nit picky details like that, it is a very nice kit, as shown here, built and photographed by Paul Boyer.

**The normal parked configuration of the Skywarrior was with the slats extended and the flaps usually down. An extendable tail bumper is provided in the Hasegawa kit but it is normally up since it automatically retracted 15 seconds after touchdown and stayed up until the landing gear was next extended.

Other kits which have been produced are the 1/84 Revell injection molded A3D, the Combat Models 1/48 vacuform (with a separate detail set) A3D, and the Collect-Aire 1/48 resin EA-3B

27 May 2013: Trumpeter has now issued a 48th scale injection molded kit of the A3D. It is very impressive, with wings and tail that can be positioned either spread or folded, flight controls and flaps/slats that be positioned, engines, a radar, etc. Given the number of variants and changes over the years, it's understandable that some errors and simplifications were made in the configuration. For some specifics and other A3D information, see:http://tailspintopics.blogspot.com/2013/05/trumpeter-148-a3d-forward-fuselage.html

Several people have provided me with information on the Skywarrior over the past 30 years or so but I want to particularly recognize Rick Morgan's contributions and his role as the subject-matter expert for the Whale as far as I am concerned (see http://thanlont.blogspot.com/2015/03/new-a3da-3-skywarrior-monograph.html). The following references are also recommended:

Jakub Cikhart suggested that I mention some of the aftermarket items available for the Hasegawa kit, specifically Eduard and Aires. Eduard produces a canopy and wheel hub paint mask set, XS112, and photo-etch details for the cockpit, speed brakes, etc, 72-258. Aires offers a set of speed brakes, wells, and actuators, #7247. (The Hasegawa kit speed brakes are not extendable.)

One of the few criticisms of the Hasegawa kit is that the cockpit detail is a bit sparse, followed by the observation that you can't discern much through the canopy anyway. Obscureco Aircraft have come to the rescue with a resin kit that provides cockpit detail for the A-3A/A-3B/KA-3B/EKA-3B. It includes three different variations on the bombardier's bombing hardware and the cockpit's rear bulkhead, with multiple options for the rearward facing seat equipment. See website.

Aeromaster issued at least two sets of decals for the Skywarrior, 72160 and 72161. Superscale also issued two decal sheets for the Skywarrior, 72-781 and 72-782.

XA3D-1: Newman R&D (aka Muroc Models) produced an excellent conversion kit for BuNo 125412. It includes resin parts for the J40 engine nacelles and pylons, the original nose and 20 mm tail turret, and the fin tip pod as well as a vacuform canopy, decals, and detailed instructions. The resin block used to form the canopy is also provided, so you can make replacement canopies if needed.

A3D-2 Bomber: One reissue of the Hasegawa A3D kit was the "Early Version." It included resin parts for the original nose and 20 mm tail turret as well as decals for VAH-1's 606AG assigned to Independence and VAH-9's 518AC. The turret is probably the best of the aftermarket options I've seen, since it includes engraved lines for the brake parachute and a recess for the tail hook. The instructions suggest scraping the later sextant framing off the canopy.

There are at least two other conversions like the one in the Hasegawa early version kit albeit without decals. One is Maintrack Models 72:43 for the "A-3A", although there was no notable difference between the -1 and -2. My impression is that the turret fairing extends a bit too far forward to properly mate with the fuselage if you cut it at the panel line indicated in the instructions: it will extend too far aft. Quickboost offers the original nose and 20 mm turret as 72 189 and 72 205 respectively. The turret is similar in configuration to the one in the Hasegawa kit and in my opinion is superior in accuracy and detail to the Maintrack version.

Versions: Cutting Edge Modelworks issued four conversion kits which all included "seamless" engine inlets:
CEC72018 A3D-1Q
CEC72019 ERA-3B
CEC72020 A3D-1P, A3D-2Q, NRA-3B, and EA-3B
CEC72021 RA-3B/A3D-2P
Decals were not included and the instructions are a bit less than complete.

15 comments:

The ERA-3B did NOT have two crew positions in the bombay. There was one crew position and one "jumpseat" which was nominally used for training new EWOs, for transporting extra crew or ground support personnel, or for taking pilots on fighter training missions and watching them puke after being yanked and banked facing sideways in the dark. We never carried a second EWO for non-training mission. I flew the ERA-3B 79-82 as EW Aircraft Model Manager, Aircraft Commander, Mission Commander, and Event Commander.

The older version of the ERA might not of had two crew positions in the back, the newer versions (read VAQ-34) with the ALT40 and ALR75 systems had a position for an Electronic Warfare Officer (EWO) and a position for an Enlisted Warfare Operator (EWOP).

I think in many instances of "Anonymous" comments, the problem is that "Anonymous" is the comment default and the commenter didn't notice it. I do screen the comments prior to them being published to weed out obvious know-nothings among other things, e.g. a compliment with a link to an ad for something unrelated to the topic. This one seemed legit.

An edited response to MadDogVAQ33 from Anonymous:"I pulled the seat position names from the ERA-3B NATOPS.VAQ-34's ERA's had two seats in the back, neither was a jump seat.When I flew in A-3's the only version that had a jump seat was the KA-3B."

Tommy, there was another Skywarrior kit produced by Hobby Systems Canada. It was a 1:48 scale vac of the A3D-2 of good quality. They were slated to produce a Banshee as well, but I think they went turtle before that could happen. Great blog, mate!

That's a great reference site. But I'm wondering at the table in the beginning of the page - you might want to take a look on the portion listing A-3Bs - it says two times 142630-142649, so I believe this is a mistake. At the same time I can't locate in the table the aircraft I'm trying to model - it's the 142403. My photos show it's a machine without CLE wing and with the older fuel vent.

I put the Hasegawa model over your wing drawings - to my relief it seems I don't have to narrow down the wing to do a non-CLE equipped aircraft. So Hasegawa only engraved the inner slots and added the engine pylon fairings to a non-CLE wing.

It's been a long time, but finally I have a web page online, where I write about my build of the Hasegawa model of the Whale. Many details you mention on these pages are addressed in my build, so if you'd like to take a look, I'd be delighted:

That's a very impressive model. When I first looked at the photos, I assumed that it was 1/48th scale, based on the finish and level of detail. I was astonished on reading farther to find that it was 1/72nd scale. Thanks for sharing it with us along with a very useful discussion of your techniques used.

Hi Tommy,Though I'm from England, UK, I've always been a fan of the Skywarrior, sadly I only ever saw one, EA-3B 146454 at Fairford in July 1991. It's great to see such superb and well thought out information (with evidence) of the type posted on your topics board.Here are some shots of a Hasegawa A-3B that I have built,[url=https://flic.kr/p/UnaR6L][img]https://c1.staticflickr.com/5/4175/34370119530_6c2cce8984_k.jpg[/img][/url][url=https://flic.kr/p/UnaR6L]Hasegawa 1:72 A-3B Skywarrior[/url] by [url=https://www.flickr.com/photos/148601493@N05/]James Thomas[/url], on Flickr

What you see venting from the under-wing masts is fuel. This is accomplished when necessary to quickly get down to the maximum landing weight, particularly important when landing on an aircraft carrier due to the weight versus speed limit imposed by the arresting system capability.

About Me

In 1956, at age 12, I lived on NAS Sangley Point in the Philippine Islands. Always enamored with airplanes, I imprinted on the Cougars, Banshees, and Skyraiders then being deployed. Not able to be a Naval Aviator because I was nearsighted, I instead became an aeronautical engineer and general aviation pilot. Now retired, I write books and monographs on U.S. Navy aircraft.